# Bioscience quiz 3.txt

 What is the buoyant force? The buoyant force is the UPWARD force on an object from it's surrounding fluid. It determines the ability of an object to float in water. Why does buoyancy occur? Becauze of the differences in pressure between the top of the object (pushing down) & the bottom of the object (pushing up) What is Archimedes principle of buoyancy? When an object is partially/fully submerged in a liquid, the amount of water that it has displaces is equal to the amount of upward force produced by the fluid. Why do some objects sink, while others float? The reason objects sink is becauze the weight of the object is > than the amount of force being produced. If the force is > than it's weight, it will RISEif the force is = to the weight, it will floatIf the force is < than it's weight, it will sink Define pressure & how to measure it The amount of force per unit area. P=Force/Area How do fluids exert pressure in a container? By molecules colliding with the walls of the container, each time exerting pressure What is the relationship b/w pressure & depth? Pressure is proportional to the depth. The deeper, the more pressure because of more water being displaced. What is the relationship b/w pressure & density? The pressure is = to the density of the object. Define viscosity. It is the measure of how easily molecules pass eachother. If a fluid is more viscous, it means it will flow slower. How viscose a fluid is is dependent on what? The attractive forces between molecules. Describe density in terms of mass & volume? Density is how much mass is in a given unity of volume. The more mass per volume, the greater the density. What effect does density have on buoyancy? The greater the density, the greater pressure What does the term displacement mean? Refers to an object when it is fully immersed in water. When it is immersed it displaces fluid to 'fit' in the water. What will happen to an object with a positive buoyancy? Why? It will float, because What will happen to an object with a negative buoyancy? Why? What will happen to an object with a neutral buoyancy? Why? What is the difference between cohesion & adhesion Cohesion refers to the attraction of like molecules to eachother (gay molecules)Adhesion refers to the attraction between unlike molecules (straight molecules) What is laminar flow? & turbulent flow? Laminar - when fluid flows in parrallel layers next to eachother with no disruptions. (ordered)Turbulent - has irregular movements of the particles. (in no order) Explain factors that cause fluid friction? What is bernoulli's principle? When an incompressible fluid is put through a narrow restriction, it tends to flow fasted AuthorCala3 ID86503 Card SetBioscience quiz 3.txt DescriptionBioscience quiz 3.txt Updated2011-05-18T03:43:29Z Show Answers